1. Field of the Invention
The present invention relates to a solid-state imaging apparatus.
2. Description of the Related Art
There is an active pixel type solid-state imaging apparatus such as a CMOS (Complementary Metal-Oxide Semiconductor) image sensor. In the solid-state imaging apparatus like this, exposure control by electronic shutter is performed by using a method which is generally called line exposure to be performing by driving a pixel matrix for each row, or rolling shutter. In this method, an exposure start time for each row is different from exposure start times for other rows, and also an exposure end time for each row is different from exposure end times for other rows. On the other hand, there has been proposed a method of achieving a global electronic shutter function in which, when exposure is performed, exposure start times for all rows are matched with others and also exposure end times for all the rows are matched with others. Here, in case of achieving the global electronic shutter function, it is necessary to simultaneously drive all pixels to control the start of the exposure and the end of the exposure. In this case, as disclosed in Japanese Patent Application Laid-Open H11-177076, a vertical controlling circuit to be used for the line exposure is exchanged for a vertical controlling circuit to be used for global electronic shutter to achieve the above simultaneous driving for all the rows.
Incidentally, in the active pixel type solid-state imaging apparatus which adopts the global electronic shutter, it is necessary to provide a holding unit for holding electrons generated in photoelectric conversion by a photodiode before these electrons are read as voltage signals to the outside of the pixel. In this regard, it is necessary to simultaneously drive the holding units respectively provided in the numerous pixels exceeding 10,000,000. However, in the related background art, a problem which is peculiar to a driving circuit of the holding unit has not been discussed up to now. More particularly, it has not been discussed what kind of vertical controlling circuit should be used to simultaneously drive the numerous holding units.
An object of the present invention is to provide the solid-state imaging apparatus which can reduce, in case of driving electrodes of the holding units, a current flowing in the vertical controlling circuit.